/Engine/Source/Runtime/Core/Public/FileCache/FileCache.h
Read a byte range form the file. This can be a high-throughput operation and done lots of times for small reads. The system will handle this efficiently.
Memory stream that contains the requested range. May return nullptr in rare cases if the request could not be serviced Data read from this stream will not be valid until all events returned in OutCompletionEvents are complete
IMemoryReadStreamRef ReadData ( FGraphEventArray & OutCompletionEvents, int64 Offset, int64 BytesToRead, EAsyncIOPriorityAndFlags Priority )